Swiss team Sauber have unveiled their 2013 Formula 1 car with the ambition of improving on last year's performance.

Sauber finished on the podium four times last year, their best ever record, but were sixth in the constructors' championship.

"The most obvious novelty on the Sauber is the nose section.

"Unlike McLaren and Ferrari, they've kept the ramp nearly all cars had last year where the bodywork transitions from the lower height demanded of the nose cone and the higher height required of the chassis, but have fitted ridges on either side.

This will be a way of trying to prevent the air going up there from spilling over the sides into the leading edge of the sidepods, which is always the case with a flat top to the car.

"That air takes up space that would be better occupied by air coming off the front wing and barge boards. It will be a very small thing - but small things all add up.

"The sidepods do look narrower - the turning vane at the front corners appear further away than normal.

"If they are narrower, that is effectively reducing the cross-sectional area of the car and means more air goes around to the rear.

"At the back, I'm surprised they've abandoned their exhaust treatment in favour of the McLaren-style approach.

"This area is a compromise between the downforce created by the exhaust gases on-throttle and the general, always-there downforce from the coke-bottle shape at the back.

"The balance between the two is difficult to get right."

Team principal Monisha Kaltenborn said she hoped the line-up of German Nico Hulkenberg and novice Mexican Esteban Gutierrez would improve on that.

"We have very high expectations and both of them know that," she said.

Sauber believe Hulkenberg, in particular, will be more effective at delivering the full potential of the car over a season than predecessors Sergio Perez and Kamui Kobayashi were.

Perez, who is now at McLaren, scored three podiums in 2012 and Kobayashi, now without a drive, one. But Sauber felt they had not maximised the potential of what was one of the year's more competitive cars.

"As for Nico we have been watching him last year and we know well how fast he is.

"We think he is a very efficient driver which means if he gets the opportunity he takes it and brings the result home."

On Gutierrez, who has been promoted from reserve driver and owes his place to the team's Mexican sponsorship portfolio, she said: "We feel it is time to bring him into F1 and I am confident Gutierrez will contribute to the success of the team."

Hulkenberg said: "Of anyone here probably my own expectations are the highest, that's part of the job. It's an exciting time and I'm just looking forward to getting to Melbourne."

Gutierrez said his ambition for his maiden season was "to be consistent at a high competitive level".

Sauber have abandoned last season's predominantly white livery in favour of graphite grey with flashes of white and red.

The new car, unveiled at the team's base in Switzerland, has a number of intriguing design features.

New rules this year allow teams to fit a 'vanity panel' to disguise the step on the top of the chassis which most had last year as a result of height regulations.

The top of the nose still has a step in it but not across its whole width - the sides of the top of the nose feature ridges which mean the step is not visible from side-on.

The car also features smaller sidepods and a change to the way Sauber are trying to use the exhaust gases for aerodynamic effect.

Last year they had a design similar to that on the world title-winning Red Bull, with bodywork swooping right back to the rear tyres to guide the exhaust gases into their optimum area where the floor meets the rear wheels and tunnels beneath that bodywork to guide airflow to the diffuser at the back of the car.

This year, they have adopted the approach taken by McLaren and Ferrari, with the exhausts in bodywork bulges at the back but no flattened bodywork beyond them.

Sauber have retained conventional push-rod front suspension rather than, like McLaren, following Ferrari's change last year to pull-rod, which has small advantages in aerodynamics and centre of gravity.